Fluid not filling container completely
The issue is (as already pointed out by Vader) your mesh is not manifold, basically meaning that it can't exist in the real world.

You can select non-manifold geometry by pressing CtrlShiftAltM in edit mode:



The reason all those edges are selected is because your mesh as no thickness. This will cause the fluid simulator (and a good many other things) to have problems.

You can partially fix this situation with a Solidify modifier (note that modifiers must be applied for the fluid simulator to take them into account), however there are still a few other problems.

I think you are better off starting over than trying to salvage this mesh, as even with the solidify modifier I don't think it will do what you want (I assume you want to have fluid everywhere except inside the letters).

An easy way to make hollow manifold text is by setting the Fill to None and adding a solidify modifier.